All-optical digital (AOD) computing has the potential to become the ultimate computing technology for speed and throughput. Computation intensive problems of the present and future, such as real time image processing and analysis, synthetic aperture radar (SAR) processing, and BM/C.sup.3 processing for SDI, may best be solved through optical rather than electronic computing. All-optical computing is a technology now ripe for development as a result of the ability to design materials (called optically bistable or non-linear materials) which mediate "light interacting with light" to provide switching and memory functions. Such a technology would have several characteristics which indicate its superiority for high throughput computation:
1. The use of light as a signal of low dispersion, maximum speed and bandwith
2. The use of optics with its inherent parallelism allowing massively concurrent computation
3. The use of light to accomplish global and "cross-talk" free interconnects not realizable electronically
4. The potential of optically non-linear materia with ultrafast subpicosecond switching.
Clearly such characteristics would be expected for the computer with ultimate performance in speed and throughput. It has the additional potential of being intrinsically radiation hardened.
The present invention approaches the characteristics of the ultimate computer in the above senses. In addition, these architectures are based on the residue (instead of binary) number system with its economy of "no carriers" (its position gives the complete number). Since this allows even further parallelism and results in the property that numerically precise computation requires no additional time.